第21卷第1期
2013年1月文章编号
1004-924X(2013)01-002006
光学精密工程
Optics and Precision Engineering
Vol. 21No.1
Jan.2013
纳米半导体复合薄膜的非线性光学性质及
其在激光器中的应用王加贤*，林正怀，张培，吴志军
（华侨大学信息科学与工程学院，福建厦门361021）
摘要：采用射频磁控溅射技术制备了Ge掺二氧化硅(Ge-SiO,)和Ge，AI共掺二氧化硅（Ge/AI-SiO;)两种复合薄膜，并进行了热退火处理形成了纳米Ge镶嵌结构。通过紫外-可见吸收谱测量，确定了两种薄膜中纳米Ge的光学带隙，并采用皮秒激光Z-扫描技术研究了薄膜的非线性光学性质。测试结果显示，在1064nm激发下得到的Ge-SiO，和Ge/AI-SiO 薄膜的非线性吸收系数分别为一1.23×10-7m/V和4.35×10-"m/W，前者为饱和吸收，雨后者为双光子吸收。把两种薄膜作为可饱和收体均可实现1.06μm激光的被动调Q和被动锁模运转。与Ge-SiO；薄膜比较，采用Ge/AI-SiO：薄
膜可以获得较窄的调Q脉冲和锁模脉冲。最后，理论分析和实验比较了两种薄膜实现被动调Q和锁模的机理，关键调：率导体复合等膜;Ge-SiO,游膜;Ge/AI-SiO,浮膜；非线性吸妆；被动调Q;载动锁模
中图分类号：O484.41;TN248,1
文献标识码：A
doi:10, 3788/OPE,20132101.0020
Nonlinearopticalpropertiesofnanometersemiconductor
compoundfilmsandtheirapplicationstolasers WANG Jia-xian',LIN Zheng-huai,ZHANG Pei,WU Zhi-jun
(CollegeofInformationScience and Engineering,HuaqiaoUniversity,Xiamen36102l,China）
Correspondingauthor,E-mail :wangjr@hqu.edu,cn
Abstract: The Ge-SiO and Ge/AI-SiO; compound films were prepared by Radio-Frequency (RF) mag netron sputtering technique, and then Ge nanocrystals were obtained in the films by a thermal annea ling treatment. The optical bandgaps of the Ge nanocrystais in the two films were calculated by meas ured UV-visible absorption spectral data, and the nonlinear optical properties of the two compound films were investigated by using picosecond laser Z-scan technique. Experiments show that the nonlin ear absorption coefficients of Ge-SiO and Ge/Al-SiO, films at 1 064 nm lasing are 1.23X107 m/V and 4. 35X 108 m/W, respectively. The former corresponds to the saturable absorption, while the latter corresponds to the two-photon absorption. Furthermore,both the Ge-SiO, and Ge/Ai-SiO, films can be as the saturable absorbers to implement the passive Q-switching and mode-locking operation for a 1. 06 μm laser. Obtained experimental results demonstrate that Ge/Al-SiO, film could achieve narro wer Q-switched pulse and mode-locked pulse than that of the Ge-SiO, film. Finally, it discusses the
收稿日期：2012-09-03；修订日期：2012-10-29
基金项目：国家自然科学基金重点项日（No.60838003)；福建省白然科学基金资助项目（No,2012J01277)；福建省青
年科技人才创新基金资助项目（No.2001J030）